A diving system audit checks that what's on board matches what the paperwork says, and that the crew knows how to use it. It reviews documentation, maintenance traceability, gas analysis, emergency procedures and crew competencies. Most findings aren't equipment failures: they're records that are missing or that don't add up.
There are two ways to experience a diving system audit. One is like a surprise inspection you have to survive, with two weeks beforehand of nerves and paperwork filled in at the last minute. The other is like an external check on something that already works every day. The difference between the two isn't decided in the week before — it's decided over the months before that.
This article explains what an audit looks at, why it looks at that, and what can be done to arrive in good shape. It doesn't go into the specific requirements of any particular scheme, because the criteria are set by whoever commissions the audit and change according to the applicable framework and the type of operation.
What exactly gets audited
A diving system isn't just the equipment. It's the whole made up of the equipment, the documentation backing it up, the procedures that say how it's used, and the people who operate it. An audit checks that those four pieces fit together.
That's the idea that's hardest to take on board for someone coming purely from mechanics: a flawless compressor can still raise a finding if there's no way to show when it was last maintained and by whom. It isn't the compressor being judged — it's the system that guarantees that compressor stays that way.
That's why most findings in a real audit aren't equipment failures. They're incomplete records, expired certificates, procedures that don't match actual practice, and missing signatures.
Documentation: the section that generates the most findings
The auditor almost always starts with the paperwork, and for a practical reason: paperwork can be reviewed without interrupting the operation, and it points to where to look next.
- Diving operations manual and procedures applicable to the work actually being done, not some other job.
- Dive plan for the current project, with its risk assessments and permits.
- Equipment certificates: pressure tests, periodic inspections, instrument calibrations and current analyses.
- Maintenance records with traceability: what was done, when, by whom, with what spare part, and what the result was.
- Qualifications and medical fitness of the crew, current and verifiable.
- Drill records and specific training for the crew on board.
- Incident log and the status of open corrective actions.
The detail that gets underestimated the most is consistency between documents. If the manual says a check is done weekly and the log shows month-long gaps, the problem isn't the gap — it's that the system is documenting a reality that doesn't exist. An experienced auditor spots that within minutes, because it's what they've spent years watching for.
The equipment, viewed through a traceability lens
The physical walk-through of the system looks for two things at once: condition and traceability. Cabinets get opened, labels get checked, serial numbers are cross-referenced against the certificates, and it's verified that what's fitted is what's supposed to be fitted.
The usual checkpoints include the gas panel and its gauges, gas banks and their labelling, compressors and filters with their replacement schedule, helmets and masks with their inspection history, umbilicals and their tests, the emergency bailout system, and lifting equipment. The logic is exactly the one described in diving equipment inspection and maintenance: every critical item has a service life, an inspection interval, and someone responsible for making sure it's met.
The recompression chamber gets a chapter of its own. Having a chamber on deck, its condition, its gas reserve, the training of whoever operates it, and the associated treatment procedure usually get reviewed with particular care, because it's the resource the response to the trade's most characteristic emergency depends on.
Gases: analysing them, and being able to prove it
The breathing gas section is audited with simple logic: you have to prove that what the diver is breathing is what it's supposed to be. That means analyses carried out with calibrated equipment, recorded results, traceability of the supply, and labelling of banks and cylinders that leaves no room for confusion.
The typical findings are about recording rather than quality: analyses that were done but not logged, expired calibration on the analyser itself, or ambiguous labelling on deck. On mixed-gas operations the bar rises, and control of the gas panel becomes a central point of the review.
Emergencies: the section you have to demonstrate, not just describe
This is where an audit stops being about paperwork. It's common for the auditor to ask to see an emergency procedure in action, or at least to ask the crew how it would be carried out, and to compare that answer against what the manual says.
It's checked that written procedures exist for foreseeable emergencies, that the crew knows them, that the necessary equipment is where the procedure says it should be, and that drills are carried out and logged regularly. Also that roles are assigned: who does what in each scenario, and who does it if that person is the one affected.
The most common finding in this section isn't the lack of a procedure, but its disconnect from reality: plans written for a different vessel, a different scope of work, or a crew of a different size. A procedure nobody has rehearsed in that specific configuration is paper, not capability.
People: competencies and familiarisation
The last leg is the crew. Qualifications and their validity get reviewed, along with medical fitness, proven experience for the role, and records of familiarisation with the specific system. This last point is often overlooked: a diver with all their paperwork in order might have been on board for two days without having formally received familiarisation with that equipment, and that's a finding.
Informal interviews are part of the method. The auditor asks people at different levels — supervisor, diver, tender, life support technician — and compares the answers. If the supervisor describes one procedure and the rest of the crew describes another, the system isn't working, however well it's written down. That's why it helps for everyone to understand the sector's general framework, including the role played by organisations like IMCA in standardising good practice, and what's required under the certification scheme being worked under.
How to actually prepare
Useful preparation means getting ahead of the auditor's scrutiny with the same rigour, and doing it with plenty of time.
The first is an honest self-audit, carried out by someone other than whoever maintains the system day to day, because familiarity breeds blind spots. The second is closing out whatever was left open from the previous audit: few things erode an auditor's confidence more than finding corrective actions from a year ago with no evidence they were closed.
The third is checking expiry dates with margin to spare — certificates, calibrations, medical fitness, qualifications — and planning renewals before they become urgent. The fourth is checking that the procedures describe how work is actually done; if practice has improved on the procedure, the procedure gets updated, and if it has degraded it, the practice gets corrected. And the fifth is keeping the documentation organised so anyone on the crew can find a certificate in a minute, not just the person who filed it.
On the day of the audit, attitude matters. Showing what's there, admitting what's missing and explaining the plan to fix it builds far more trust than hiding a folder away. An experienced auditor spots window-dressing straight away, and once they do, they start looking at everything else under a magnifying glass.
The findings that come up most often
Anyone who's been through several audits will recognise a catalogue of classics straight away, and almost all of them belong to the same family: the real system works better than its documentation is able to prove.
- Records with gaps. Checks that get done but not logged, or that get logged in a batch at the end of the week.
- Certificates lapsed through oversight, not for lack of maintenance: the inspection was done, the paperwork just wasn't updated.
- Generic procedures inherited from another project or another vessel, describing a configuration different from the one actually in place.
- Open corrective actions from earlier audits, with no evidence of closure or an owner assigned.
- Unlogged familiarisation for recently joined crew members.
- Simulacros escasos or always covering the same scenario, the easiest one to run.
- Etiquetado ambiguo in gas banks or backup equipment.
None of these findings on its own points to a negligent crew. They point to a system that relies on two or three people's memory instead of on a procedure, and the problem shows up exactly on the day those people aren't on board.
Why this matters to a rank-and-file diver
It might look like an office matter, but it isn't. The audit is one of the few external mechanisms that force the equipment someone's life depends on to be maintained, logged and verified. When it works well, the diver benefits directly: inspected helmets, analysed gases, rehearsed procedures and an operational chamber.
And there's an added professional reason. In a sector where reputation travels fast, working on operations that pass audits without drama is also a way of building a solid track record, something that shows both when looking for a campaign through the sector's agencies and job boards and when aiming for supervisory roles. A professional who understands how a system gets audited doesn't just have an easier time on the day of the visit — they understand the trade better.
Frequently asked questions
Who audits a diving system?
It depends on the context. It can be audited by the client before contracting, by the company itself as internal control, by a classification society, or by an independent auditor on behalf of a third party. The specific criteria and their scope vary depending on who commissions the audit and under what framework it's carried out.
Is an audit the same as an equipment inspection?
No. An inspection looks at the physical condition of a specific piece of equipment. An audit looks at the whole system: equipment, documentation, procedures, maintenance and people. Equipment in perfect condition can still raise a finding if there's no way to show how it got that way.
What's a finding and what's an observation?
A finding is a non-conformance against the audited criteria and requires a corrective action. An observation flags something that could be improved, or a risk that a non-conformance could arise in future, without being one yet. The exact terminology depends on the audit scheme.
Can an audit stop the operation?
It can make it conditional. If a finding comes up that directly affects the safety of the dive, the normal course is not to dive until it's closed out. The final call rests with whoever holds responsibility for the operation, not with the auditor.
What's asked of a rank-and-file diver during an audit?
That they can explain what they do and why. It's common for the auditor to ask anyone on the crew about the emergency procedure, where a key piece of equipment is, or when the last drill was. Answering naturally is the best sign that the system is actually alive.
Published 7 September 2026 · By Arthur More, professional saturation diver
Photo: oskay · CC BY via Openverse